pinging and smoke under load

[bdepedro]

Ok, I've been having an issue under heavy acceleration. The engine will ping and I get a lot of grey smoke. Otherwise the car runs great. I've checked the timing and replaced the bushings and springs in my dist. I'm using the biggest springs the kit came with. I'm wondering if my secondary jets are too small. I can't remember what they are but am thinking 66s. I haven't tried increasing that but might be my next step. I'm running 10.5:1 compression and should be ok with 93 octane. I'm not sure what else to check other than that. Any suggestions would be helpful. Thanks.

Oops, forgot to mention: Engine is a bored 289, .512 lift/292 duration cam, heads have been ported/polished, heads and block decked. Can't remember valve sizes. 570 Holly Street Avenger carb, Edlebrock Performer intake...

 

[robbz28]

Sounds like you might actually be rich with the smoke...but the pinging could just be valve clatter from the high compression. I had a 69 camaro I had built with a very similar setup @ 10.5:1....if i was cruising around 3000 it was fine, but if i pushed down the pedal it would clatter ever so slightly....try a capful of marvel mystery oil in your next tank of gas and see if that helps things out.

 

[bdepedro]

It's a lot more smoke than I would think would be from a rich mixture. I may be wrong but I will try some Marvels and see how it responds.

 

[robbz28]

Do you end up with little black speckles on the back of your car? On your bumper, etc?? Make sure the back of the car is clean, then take the car for a 10 minute drive, then take a white paper towel and rub down your bumper, if there is a black film on it then you are more than likely rich....this can be from too much jet, but also could be from timing being off and not getting a proper ignition and blowing gas out the exhaust.

 

[bdepedro]

No, I'm not getting that but I know exactly what you are talking about. I used to get that with my old carb. I've rejetted the primary jets, replaced the distributor springs and bushings and reset the timing. It helped some but still does it. Since it occurs when the secondaries open I'm wondering if I need to change those jets.